Metz Stephan, Damoser Petra, Hollweck Regina, Roggel Rudolf, Engelke Christoph, Woertler Klaus, Renger Bernhard, Rummeny Ernst J, Link Thomas M
Department of Diagnostic Radiology and Institute of Medical Statistics and Epidemiology, Technische Universität München, Ismaninger Str 22, 81675 Munich, Germany.
Radiology. 2005 Mar;234(3):776-84. doi: 10.1148/radiol.2343031805.
To evaluate the influence of different detector radiation doses and peak kilovoltage settings on diagnostic performance and radiation dose at posteroanterior (PA) chest radiography performed with an amorphous silicon flat-panel detector (FPD).
All examinations were performed by using a digital FPD. PA chest radiographs of an anthropomorphic chest phantom were obtained with detector radiation doses of 2.50 microGy (system speed, 400), 1.56 microGy (speed, 640), and 1.25 microGy (speed, 800) and with peak kilovoltage values of 100, 120, and 140 kVp. Four types of simulated lesions-nodules of different sizes, polylobulated lesions, interstitial-nodular lesions, and interstitial-reticular lesions-were superimposed on the phantom. After four radiologists assessed all of the images, receiver operating characteristics analysis was performed. In addition, the entrance surface dose was measured and the effective dose was calculated.
Reduced detector dose led to significantly decreased diagnostic performance in overall lesion detection (P <.05). However, over pulmonary areas only, this effect could not be seen. With use of the same kilovoltage values, reducing the detector dose, even to 1.25 microGy (speed, 800), did not lead to significantly decreased lesion detectability. In terms of diagnostic performance and effective dose, 120 kVp was the most effective.
Standard PA chest radiographs should still be acquired at a detector dose of 2.50 microGy (speed, 400) with 120 kVp to yield the highest diagnostic performance. However, when the present analysis was focused on the lung fields only, no significant loss in diagnostic performance could be demonstrated, even after a 50% reduction in radiation dose.
评估不同探测器辐射剂量和峰值千伏设置对使用非晶硅平板探测器（FPD）进行后前位（PA）胸部X线摄影时的诊断性能和辐射剂量的影响。
所有检查均使用数字FPD进行。对一个仿真人体胸部模型进行PA胸部X线摄影，探测器辐射剂量分别为2.50微戈瑞（系统速度，400）、1.56微戈瑞（速度，640）和1.25微戈瑞（速度，800），峰值千伏值分别为100、120和140 kVp。在模型上叠加四种类型的模拟病变——不同大小的结节、多叶状病变、间质结节状病变和间质网状病变。在四位放射科医生评估所有图像后，进行了受试者操作特征分析。此外，测量了体表入射剂量并计算了有效剂量。
探测器剂量降低导致总体病变检测的诊断性能显著下降（P <.05）。然而，仅在肺部区域，这种影响未被观察到。在使用相同千伏值时，将探测器剂量降低至1.25微戈瑞（速度，800），也不会导致病变可检测性显著下降。在诊断性能和有效剂量方面，120 kVp最为有效。
标准PA胸部X线摄影仍应以2.50微戈瑞（速度，400）的探测器剂量和120 kVp进行采集，以获得最高的诊断性能。然而，当本分析仅关注肺野时，即使辐射剂量降低50%，也未显示出诊断性能有显著损失。
